An airborne disease is any disease that is caused by pathogens and transmitted through the air. Such diseases include many that are of considerable importance both in human and veterinary medicine. The relevant pathogens may be viruses, bacteria, or fungi, and they may be spread through coughing, sneezing, raising of dust, spraying of liquids, or similar activities likely to generate aerosol particles or droplets. Strictly speaking airborne diseases do not include conditions caused simply by air pollution such as dusts and poisons, though their study and prevention may be related.